package main 
import (
	"fmt"
)
func main() {
	var a int = 10
	var b int = 20
	a = a + b
	b = a - b  //a + b - b
	a = a - b  // a + b - a - b + b
	fmt.Printf("a的值是%v,b的值是%v", a, b)
}